kennedy drew this blistering response from his opponent, lloyd benson. >> senator, you are no jack kennedy. >> the debate in 1992 was described as a free-for-all with dan quayle and al gore continually interrupting each other. >> in foreign countries -- >> just not -- >> foreign aid -- senator, it's in your book. >> it's just not true. >> vice president dick cheney and senator john edwards barely kept their debate civil in 2004, with cheney blasting edwards for his attendance record in congress. >> the first time i ever met you was when you walked on the stage tonight. >> in thursday's debate, biden is expected to go after paul ryan on issues like medicaid, social security and foreign policy. >> i wouldn't be surprised if you got a zinger or two from joe biden. i don't think he's worried about being perceived as talking down to paul ryan. >> and the personal moments could matter, too. biden showed his emotional side during his last debate. >> look, i understand what it's like to be a single parent. when my wife and daughter died and my two sons were gravely injured, i understand what it's